Communication networks such as the subject one are well known in the computer communications field, the most widespread examples being the local and metropolitan area networks, LAN and MAN respectively, realized according to a family of IEEE standards commonly known as the family of IEEE 802 standards. The latter networks use a shared transmission medium for the transmission of data between the local terminals. The use of this shared transmission medium has to be arbitrated and the procedure used therefor, generally known as media access protocol MAC, forms the main part of the above standards and determines to a large extent the computer network link type to be used.
Although these known networks, developed separately from the public telecommunications network, are presently the best known solution for the specific problems associated with computer communications, it is widely appreciated that they are intrinsically expensive with regard to installation and maintenance costs. The above is all the more true if only a small number of local terminals use the network as then the network cost per terminal considerably increases due to the relatively large fixed costs associated with wiring, control and communication with remote terminals, i.e. terminals from outside the network, which has to be performed via a separate module known as bridge/router module. Large maintenance costs occur when a plurality of parallel networks called collision domains, each having their own fixed costs, are necessary in a same site due to limitations on the number of local terminals connected to a same network. Indeed, a change in network traffic conditions then often requires physically changing the wiring of these networks in order to obtain more suitable collision domains.
It can thus be seen that the above known computer networks while providing a good and, thanks to large sales figures, cheap access method for terminals tend to be rather expensive over-all due to their rather expensive wiring and network termination equipment, especially when communication between the local and remote terminals is needed, and due to their lack of flexibility once implemented. These drawbacks are most outspoken when a number of small and distributed clusters of terminals need to be interconnected and when a very large number of terminals in a same site need to be able to communicate not only with each other but also with remote terminals.